I liked the business app especially for shortcuts, auto-replies and other stuffs. But yes, official APIs is deal-breaker.
NOTE: Many applications and websites somehow are already using custom APIs (or something). Ex. Airlines sending booking details as WhatsApp message, flight/bus status and so on.
I work for one of the largest travel groups, I'm actually working on flight notifications, and they don't want to go there - no idea how other airlines or travel groups do it.
Ha think about all of the surface area on Facebook employees faces/arms that you could tattoo advertising on. I wonder if they have considered the financial opportunity cost there?
And apparently that's what they proposed to Sandberg, according to the article, but the financial projections were nowhere near what ads would bring.